Sheet metal forming brake



J. M MINOR SHEET METAL FORMING BRAKE I Nov 1, 1949.

3 Sheets-Sheet 1 Filed Dec. 2, 1947 I "INVENTOR. /0%/7/ ZMZ 7707 ATTD R N EYS Nov 1, 1949. J. M. MINOR I 1 2,486,428

SHEET METAL FORMING BRAKE Filed Dec. 2, 1947 s Sheets-Sheet 2 $5 a) Q w/hM/vz'nor INVENTOR.

J. M. MINOR SHEET METAL FORMING BRAKE Nov 1, 1949.

' 3 Sheets-Sheet 3 Filed D66. 2, 1947 ATI'U RN EYS Patented Nov. 1, i949 UNITED STATES PATENT OFFICE SHEET METAL FORMING BRAKE John M. Minor, Walteria, Calif.

Application December 2, 1947, Serial N 0. 789,194

4 Claims. (Cl. 153-48) My present invention relates to the general class of sheet metal bending machines, or brakes. of the reciprocating type, and morespecifically to an improved sheet metal forming brake of the manually activated and eccentrically operated type including a vertically reciprocable die and a complementary stationary die. While the principles of my invention may be embodied in a heavy duty appliance, it is especially designed and hereinafter described and illustrated as a light-weight and light-duty metal bending appliance for use as a hobby in the formation of angular, rounded, and tubular, as well as radius pieces of work.

The light-weight and portable appliance may be attached for use to a work bench, or mounted in a vise as a support, and means are provided whereby the appliance may be manually activated with a demountable wrench or wrenches, or by the utilization of a treadle arrangement in combination with the wrench or wrenches.

The complementary uppertmovable dies and lower stationary dies are removable and interchangeable for the production of various products, and the mechanism is readily adjustable for various steps in the process of bending sheet metal.

The invention is embodied in a minimum number of parts that may with facility and low cost of production be manufactured, and the parts may be assembled with convenience, to provide a quick-acting, durable, and efficient, metal bending appliance that is accurate in the performance of its functions, and which may be manipulated with ease.

The invention consists in certain novel features of construction and combinations and arrangements of parts as will hereinafter be described and more particularly set forth in the appended claims.

In the accompanying drawings I have illustrated a complete example of a physical embodiment of my invention in which the parts are combined and arranged in accord wih one mode I have devised for the practical application of the principles of the invention. It will however be understood that changes and alterations are contemplated and may be made in these exemplifying drawings and mechanical structures, within the scope of my claims without departing from the principles of the invention.

Figure l is a front elevation of a metal bending appliance .embodying my invention, and equipped with a single wrench for activating the operating parts.

2 .Figure 2 is a top plan view of the appliance in Fi 1.

Figure 3 is a view in elevation showing a portion of the end of appliance as seen from the right in Figs. 1 and 2.

Figure 4 is a 'vertical transverse sectional view as at line 44 of Fig. 1.

Figure 5 is a view in end elevation similar to Fig. 3, with the movable die partially depressed.

Figure 6 is a detail sectional view at line 6-6 of Fig. 5 showing the operating shaft with its eccentric for pulling down or depressing the movable die.

Figure '7 is a detail sectional view transversely of the operating shaft showing the control and stop means for the partially rotatable or rock shaft that operates the vertically depressible upper die, at line of Fig. 1.

Figure 8 is a detail sectional View at line 8-8 of Fig. 1, looking upwardly.

In this specific form of the invention I employ a frame including a horizontally extending die carrying base plate I of suitable metal and disposed in a vertical plane, which is provided with a pair of spaced angle iron brackets as 2, 2, that extend horizontally and are provided with holes for screws or bolts by means of which the supporting frame may be attached to a bench or table. The supporting frame also includes a pair of spaced standards or columns 3, 3, of angle irons, and the base plate, brackets and columns are rigidly united, as by welding, to provide a supporting structure for the operating parts of the appliance. If desired, the appliance may be supported in operative position by mounting the base plate in a vise that is also rigidly mounted or supported for the purpose. I

A horizontally extending operating shaft 4, which is partially rotatable, is journaled to rock in spaced bearings as 5, 5, that are preferably welded to the rear face of the base plate I, and the rock shaft is equipped with an integral, or welded, stop lug 6, for co-action with a set screw 1 that is threaded through a hole in the base plate, in limiting the rotary movement of the rock shaft, and the braking angles imparted to the work may positively be controlled by turning the screw 1 which is readily accessible at the front of the appliance.

The shaft 4 at its opposite ends terminates in hexagonal heads 8, 8, arranged eccentrically of the shaft, and one or two removable and hand manipuated wrenches, as 9, each having a complementary nut-head 1-0, are employed for turning the rock shaft in its bearings. As indicated.

in Fig. 2, the wrench 9 may be equipped with a welded ring 9A to which a treadle mechanism may be attached, and this mechanism may be utilized in adjusting the die mechanism to the work, or in operating the shaft.

Inset from the hexagonal heads 8 the shaft is equipped with two integral or welded eccentrics or circular cam disks l I, II, that turn with the shaft when the wrench is turned, and a pair of eccentric straps I2 are mounted upon the eccentric disks, against retaining flanges I3, I3 of the disks, it

being understood that the hexagonal heads and L eccentrics are integral with or welded to the shaft.

Each of the eccentric straps is provided with a tangentially arranged operating yoke or upright arm l4 that is adapted to depress or pull down the movable die member of the bending appliance or braking mechanism, and for this purpose the arms terminate in arched bearing-heads l5, each having a bearing saddle 16 that engages over the upper edge of a vertically movable head or die carrying plate [1.

This horizontally extending plate I! is disposed in a vertical plane, and it is supported or resiliently suspended in front of the two upright columns 3, 3, by means of a pair of hoop springs l8 that automatically retract or lift the die head or plate after each stroke of the wrench or wrenches. The hooked front end of each spring, as I9, is anchored in a hole 20 of the plate or head l1, and the rear end 2| of the springs is fitted in a hole of a column or upright 3, a tension pin 22 being mounted in the column for stabilizing the retracting spring.

Along the lower edge of the vertically movable or depressible header or plate ll, multiple tabs or dieholders 23, are mounted for supporting the male die, and these spaced holders are each secured by means of a bolt or screw 24 and-nut 25, as indicated. Each holder or tab is provided with a retaining spring 25 secured by the screw or bolt 24, and as seen in Figs. 1, 4, and 5, the cylindrical male die 2'! is fashioned with a thin steel neck portion 23 that is retained at its upper edge in the alined complementary slots of the holders or tabs.

A lower, stationary, female die 29, of semicircular shape in cross section is located beneath the depressible upper die, and the lower die is mounted by its shank 30 in die-holders 3| that are secured by bolts or screws 32 to the base plate I, and retained as by springs 33; these holders being substantially of the same type as the holders 23 of the upper die.

For gauging or positioning the work with relation to the dies, a horizontally extending gauge bar 34, here shown as of angle iron shape, is provided with end wings or flanges as 35, 35, and adjustably mounted upon a pair of parallel spaced supporting rods 36, 3B, the front ends of which are threaded into bores of the two columns or uprights 3, 3. The gauge bar is adjustable in a horizontal plane toward and away from the dies, and the bar is mounted upon the rods by means of a pair of collars or rings 31 surrounding the rods. Each collar is fashioned with an integral stud screw 33 that passes upwardly through a hole in the wing portion of the gauge bar, and the studs or screws are each equipped with a clamping nut 39 that may be turned home to clamp the gauge bar in adjusted position.

The cylindrical male die 21 is initially split or slotted to receive the lower edge of the flat neck portion 28 which is brazed, soldered, or welded therein, and the presence of this comparatively thinneck portion of the upper die, in co-action with the lower die 29 permits the braking of a flat sheet of material into a substantially complete cylindrical tube.

As an example of the operation of the metal bending appliance in the formation of a cylindrical tube by the dies in Figs. 3, 4, and 5, a sheet of metal is placed in horizontal position with its front (or left end in the drawings) resting on the stationary die 29, and its rear end backed against the gauge bar. By a swinging stroke of the I wrench the shaft is rocked to depress the upper die and thereby press the front end of the sheet into the lower die to form an arcuate curl of approximately ninety degrees, after which the wrench is retracted by hand, and springs I8 automatically lift the upper die. Then the position of the sheet is reversed or turned on its center through an angle of one hundred and eighty degrees to set a fiat end of the sheet on the lower die, and a second curl .of approximately ninety degrees is formed in parallelism with the first curl, the gauge bar having been adjusted for this second step. Again the gauge is adjusted and the sheet with its curled edges is placed on the lower die with its rear curl against the gauge bar and its central portion centered on the female die; then by another stroke of the wrench the central portion of the sheet is fashioned with a one hundred and eighty degree bend and the two curled edges are simultaneously wrapped around the cylindrical upper die, thus forming a split cylindrical tube on the upper die. This tube may readily be slipped along the movable die and removed from one of its ends, and the walls of the slotted or split tube may be welded or otherwise united as desired.

The dies are interchangeable with other shapes and sizes of dies which may be angular, or rounded in cross section, for the production of various kinds of work.

It will be obvious that the appliance may also be used for other purposes, as for instance, as a shearing press or cutter, by substituting a shearing blade for the upper die for co-action With a stationary guide plate that is substituted for the lower die.

Having thus fullydescribed my invention what I claim as new and desire to secure by Letters Patent is:

1. In a sheet forming machine, the combination which comprises a stationary die carrying base plate, a pair of spaced vertically disposed standards extended upwardly from the said base plate, an upper movable die carrying plate slidably positioned against the faces of the said standards, springs carried by the standards, said springs being arranged to maintain the upper die carrying plate against the faces of the standards and to act to urge said plate in an upward direction, a shaft having off-set crank sections therein rotatably mounted in the said base plate, and arms carried by the crank sections of the shaft and extended upwardly into coacting relation with the said upper die carrying plate.

2. In a sheet metal forming machine, the combination which comprises a stationary vertically disposed die carrying base plate, an upper travelling vertically disposed die carrying plate superimposed above the base plate, a plurality of spaced die holders carried by the coacting edges of the base and superimposed die carrying plates, standards against which the said die carrying plates are slidably positioned, resilient means arranged to maintain the upper die carrying plate against the faces of the standards and to act to urge the said plate in an upward direction, parallel horizontally disposed rods extended rearwardly from the said posts, a gauge bar aligned with the meeting point of dies carried by the plates slidably mounted on said rods, a shaft rotatably mounted in the base plate, said shaft having eccentrically positioned crank pin sections therein, upwardly extended arms having hubs rotatably mounted on the said crank pin sections of the shaft and provided with arcuate saddles in the upper end for grippin the upper edge of the said upper die carrying plate, and a hand lever on said shaft for actuating the said upper die carrying plate through the arms.

3. In a sheet metal forming machine, the combination which comprises a stationary vertically disposed base plate, a travelling vertically disposed die carrying plate superimposed above the base plate, a plurality of spaced die holders carried by the coacting edges of the base and superimposed die carrying plates, standards against which the said die carrying plates are slidably positioned, resilient means arranged to maintain the upper die carrying plate against the faces of the standards and also to act to urge said plate in an upward direction, parallel horizontally disposed rods extended rearwardly from the said standards, a gauge bar aligned with the meeting point of dies carried by the plates slidably mounted on said rods, a shaft rotatably mounted on the base plate, hexagonal elements eccentrically mounted on the ends of the shaft, arms having hubs with hexagonal sockets rotatably mounted therein positioned, through the said sockets on the hexagonal elements at the ends of the shaft, said arms extended upwardly and having recesses in the undersurfaces of the upper ends thereof, saddles in the recesses of the upper ends of the arms straddling the upper edge of the said die carrying plate, and a hand lever having a hub with a hexagonal socket therein positioned on a hexagonal element at the end of the shaft.

4. In a sheet metal forming machine, the combination which comprises a stationary vertically disposed die carrying base plate, a travelling vertically disposed die carrying plate superimposed above the base plate, standards against which the said die carrying plates are slidably positioned, U shaped springs carried by the stand ards said springs being arranged to maintain the upper die carrying plate against the faces of the standards and to act to urge said plate in an upward direction, a shaft rotatably mounted on the base plate, said shaft having eccentrically positioned crank pin sections therein, upwardly extended arms having hubs rotatably mounted on the said crank pin sections and provided with arcuate saddles in the upper ends for gripping the upper edge of the said die carrying plate, a hand lever on said shaft for actuating the said die carrying plate through the arms, said shaft having a lug positioned thereon intermediate of the ends thereof, and an adjustment screw threaded in the base plate positioned to engage the said lug of the shaft to limit rocking movement of the shaft. JOHN M. MINOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

